"The intertextual relations of the text are never purely literal. Fiction draws not only on other fiction but on the knowledge of its period, discourses in circulation which are themselves sites of power and the contest for power." (Belsey 433)
Belsey goes on to use Shakespeares Macbeth as an example of this power in cultural fiction. She sites all the inferences that Macbeth has on its culture which are not limited to the obvious "vaulting ambition" which is throughout many of Shakespeares plays.
There needs to be knowledge of ones culture to write a story or poem that readers can relate to. This doesn't mean one must limit themselves to only their culture, exploring others can add many dimensions to a writers work, but an author is still going to be influenced by their own culture first and that will come out in their writing. Shakespeare shows us this in his writing and the power struggles that consume so much of his work. Belsey goes on to list all that these power struggles and ambitions encompass. What we think of in terms of power can be stretched to include many different aspects of a culture.